Most residences and small commercial establishments, inclusive of single-family homes, multi-family dwellings, and residential communities, require electricity and natural gas that is provided by connections to local utilities. Electricity is typically provided from a utility grid, and it can be used to power electric appliances. Natural gas is typically provided from a natural gas utility, and it can provide thermal heat for appliances, clothes dryers, hot water heaters or other uses.
The two energy sources are not interchangeable, as one must purchase appliances based on a particular energy source (e.g., an electric furnace or a gas furnace). As a result, the homeowner is subject to the seasonal price adjustments of both natural gas and electricity, typically paying more for each energy type during peak seasons (summer for electricity, winter for natural gas). In order to change the energy profile of a residence, a homeowner would then have to buy different appliances. For example, the homeowner could change the energy profile of a residence by replacing a gas furnace with an electric furnace.
Additionally, a homeowner might supplement gas or electricity requirements with alternative energy sources. For example, solar energy or wind power might be used to supplement utility-provided energy or possibly provide complete independence from utility-provided energy. Usually this substitution of alternative source energy for utility-provided energy is direct and requires an industrial-strength battery to compensate for periods when the alternative energy source is not producing energy (e.g., on a cloudy day for solar power) or when peak current events utilize more energy than the alternative source can provide (e.g., starting up an air conditioner).
The hydrogen fuel cell provides one method to interchange natural gas and electricity. Hydrogen can be produced from natural gas through a process called reformation, and it can be produced from electricity using a process called electrolysis. When processed through a fuel cell, hydrogen provides both electricity and hot water. One natural complement to the fuel cell is the use of renewable sources of energy, like photovoltaic solar panels or wind generators, to provide electricity and thermal energy that can be used directly by the building or used to supply electricity for electrolysis which then produces hydrogen for later use.
One other capability of the fuel cell is that it is a “cogeneration engine,” in that its processing of hydrogen simultaneously results in the production of both electricity and thermal energy (in the form of steam or hot water). Thus, a single energy source, such as natural gas, or multiple energy sources inclusive of natural gas, renewables-based electricity, and utility-supplied electricity, can be used to produce hydrogen, which in turn can be converted into electricity and thermal energy.
Homeowners typically have one other energy requirement: transportation fuel, which is usually purchased in the form of gasoline. For many homeowners, gasoline can be the most significant component of that homeowner's monthly energy bill. Gasoline differs from electricity and thermal energy because it is typically a static, rather than dynamic, energy requirement. One acquires a specific volume of gasoline at a specific time when refueling a vehicle; electricity and natural gas needs, on the other hand, can change literally moment to moment.
U.S. Pat. No. 5,432,710 (“Ishimaru”), for example, applies the hydrogen fuel cell and its cogeneration capabilities to electricity and thermal energy requirements of the home. However, the '710 patent does not take transportation fuel into account. Similarly, U.S. Patent Pub. No. US2002/0082747 (“Kramer”) addresses the thermal and electric energy requirements of a building, but it too excludes transportation fuel needs from its energy profile.
For transportation fuel needs there is lack of a refueling infrastructure for hydrogen cars and sufficient capacity in the existing electricity grid for large numbers of cars that use electricity, such as plug-in hybrids (“PHEV”) or pure-electric vehicles (“PEV”). This has resulted in a “chicken-egg” enigma between automakers and energy companies. Energy companies are reluctant to invest billions of dollars in building or converting service stations to provide hydrogen fuel in the absence of a sufficient base number of hydrogen-powered (viz., fuel cell or hydrogen internal combustion) cars that require such fuel. Electric utilities are reluctant to invest in construction of additional generating plants to provide for the electricity demands of large numbers of PHEVs and PEVs until the fleet of such vehicles becomes substantial. Automakers are reluctant to invest billions of dollars in retooling or building manufacturing facilities to produce hydrogen cars or PEVs/PHEVs in the absence of a refueling infrastructure that can accommodate them.
Therefore, there exists a need to provide an improved method and apparatus for optimizing utility-supplied and alternative energy sources in order to minimize total energy costs while at the same time accounting for transportation fuel needs.